My long range goal is to learn the biological function of interspersed repeated DNA sequences. Most of the interspersed repeats in human DNA are 300nt long, and most or all of these 300nt repeats belong to a single family of sequences, the Alu family. Available base sequences of this family suggest it may serve several important functions. By base sequencing genomic clone representatives of this family we will learn if variants of the sequence designate subgroups which may have distinct functions. This study will also identify the genomic sequences which immediately flank the Alu family members. We know nothing of other families of interspersed repeats in human DNA: their existence, copy number, genomic distribution, transcriptional activity and base sequence. We will examine human genomic clones for other "non Alu family" interspersed repeats. As we identify new families of interspersed repeats we will characterize them with respect to all of these unknown properties. Many of the suspected functions of interspersed repeats are associated with some aspect of regulating gene expression e.g. hn RNA processing, transcriptional control etc. By mapping and partially sequencing human genomic clones which contain structural genes we will identify any non random arrangement which the Alu family, its subgroups and non ALu family interspersed repeat have toward genes